Source Wireframe Kit - Library of 537 blocks for desktop and mobile prototyping
VectorScribe - The missing toolbox for Adobe Illustrator.
Contra Wireframe Kit - Open source wireframe kit for design and prototyping 🚀
Fabricating Alternatives - AI-powered card deck to help ideation & brainstorm
Platforma - Wireframe library of layouts and UI elements
SnapUp - Wireframe faster / create amazing user interfaces